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Where should solar heater water drain to?

When I shut the pump off, the water drains, but it drains back through the cartridge filter and into the pool through the skimmers... So it is basically back washing and crud goes
Back into the pool.

I have an easy touch system to instal but it is not hooked
Up yet, so right now the plumbing is left lined up through solar and I was going to use
The timer
On the intelliflo to start/stop at 830am/530pm.

But the dirty backwash has me wondering if the plumbing is
As it should be or if this is
Just a "dirty little secret" of solar.

Re: Where should solar heater water drain to?

You may need to add a one way check valve into the system to prevent backflow, these can often be found at Lowes and other big box home stores in the plumbing section. (looks like a section of PVC pipe with a fat part in the middle).

Re: Where should solar heater water drain to?

Make that "do need" to install a check valve between the filter and the solar line. Having a check valve after the filter is routine/standard when you have a solar system. You usually also have a check valve on the solar return pipe coming down from the roof, so the pump can't force water up to the panels backwards when they are turned off.

Where should solar heater water drain to?

Ok. Thanks. I ordered two pentair 2" check valves when the pool
Was built last year. One was installed stubbed ready for solar. I'll have to get the other one in.

I'm not sure the panels can drain with this in place tho. And I thought that was the point of the vacuum breaker. I know freeze protection is mandatory, but I
Also Thought stagnant Water Was not supposed to Sit In the panels... Hmmm

Re: Where should solar heater water drain to?

Neither check valve should interfere with the panels draining down at all. The check valve by the filter simply forces the water to drain down to the return line, instead of back through the filter. While the check valve on the solar return line allows water to come down the line towards the pool, but does not allow water to go backwards up towards the panels.

Re: Where should solar heater water drain to?

The one check valve should be between the filter and your solar valve. But for the pool to drain you need the solar valve to be "leaky". I used a Pentair solar valve that has a small check valve also built into the diverter, but some people just drill a small hole in the diverter valve so the water can pass through.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone

Where should solar heater water drain to?

Ok. That makes sense. I am not sure yet how the automation system handles calls for heat on days with intermittent clouds rolling through. When the set point has not yet been met, but the temp from the solar heater mounted sensor is not at or above the trigger temp, does the easy touch just shut the pump down or does it turn the solar diverter? Or both. Or does it depend on the filtering schedule? Ie, if it is set to filter during the day, I would think the diverter valve would turn and the intelliflo would run at the scheduled filter rpm.

If the system is set to filter at night (say because of tiered electrical charges) when the solar heater temp falls below the trigger, does the pump just shut down but leave the system lined up for solar?

Re: Where should solar heater water drain to?

Solar will only come on if the filter pump is scheduled to be on. If you schedule the filter to run at night, solar won't work.

The pump runs the entire time, with the solar valve actuating to send water to the panels only when they are several degrees warmer than the pool water and the pool water is not yet up to temperature.

With an IntelliFlo pump, the system can be setup so that the pump speed is different for solar and non-solar. When solar comes on the pump will speed up and when solar turns off the pump will slow down again. So you could run at an extremely low speed without solar and then have the solar programmed to bring the speed up to something appropriate when the panels are active.

Re: Where should solar heater water drain to?

I found this interesting because I had solar put on my pool by a very reputable company with 5 stars on Yelp and a ton of reviews and they DID NOT put the check valve after the filter before the solar valve. In the same way that this poster describes when the pool pump shuts off the solar drains out of the panels and then flushes the filter back out to the pool. I remember when it was installed that I questioned the need for a check valve and the owner of the solar company told me that the builder should have put one before the pump (hmmm, no).

So anyway, I'm going to install a FlowVis check valve after my filter before the solar valve to fix the issue but wanted to mention that even the "pros" don't seem to get it right sometimes.

Re: Where should solar heater water drain to?

Draining the input side of the solar can be achieved a few different ways. One that's already been mentioned is a small hole in the input side check valve flapper. I like a bypass line plumbed between the solar input and output lines. This is plumbed on the solar side of the check valves previously mentioned. A 2-way or ball valve on the bypass is kept nearly closed so that it allows only a small amount of water to bypass the solar panels while operating, and when the system shuts down, the input side of the solar circuit and the panels can slowly drain back down the solar input pipes, through the bypass and partially open valve to the return side.

- - - Updated - - -

...and anyone that plumbs a pool so that a filter backwashes into the pool is not worthy of the "pro" moniker!! The term numbskull seems closer to the mark.